The Trace Telescope Point Spread Function for the 171 Å Filter

We perform an analysis of the TRACE telescope blur from EUV images. Theblur pattern is discussed in terms of the telescope point-spread function (PSF) for the 171 Å filter. The analysis performed consists of two steps. First, an initial shape for the PSF core is determined directly from TRACE EUV images. Second, the blind-deconvolution method is used for obtaining the final PSF shape. The PSF core peak is fitted by analytical functions to determine its parametric characteristics. The determined PSF includes the core central peak and peaks caused by diffraction effects inherent in TRACE EUV data. The diffraction portion of the PSF is studied theoretically in the Fraunhofer diffraction limit. The temperature dependence of the TRACE PSF shape is investigated for a selected temperature range. We also discuss general properties of the obtained PSF and its possible applications.